For service and parts needs, visit your dealer. You will receive genuine GM parts and GM-trained and supported service people.
Genuine GM parts have one of these marks:

Vehicle Care
California Proposition 65 WarningRear Side Door Upper Hinge and Lower Hinge Replacement
Preliminary Procedure
Remove the rear side door. Refer to Rear Side Door Replacement.
Rear Side Door Hinge Bolt (Qty: 4)
Caution: Refer to Fastener Caution in the Preface section.
Tighten
25 N·m (19 lb ft)
Reart Side Door Hinge
Procedure
Adjust rear side door as needed. Refer ...
Storing the Tire Sealant and Compressor Kit
The tire sealant and compressor kit is located in the trunk, under the load floor,
behind an access panel.
To remove the kit:
1. Open the trunk.
2. Turn the left knob counterclockwise and the right knob clockwise, 90 degrees,
at the same time. Then pull the access panel rearward and up to r ...
Steering Angle Sensor Calibration Warning
Warning: For vehicles with electric power steering (EPS) and without
a vehicle stability enhancement program, the steering angle sensor
MUST always be calibrated after the battery has been disconnected. Failure to
calibrate the steering angle sensor could limit the operation
of the EPS system ...